JPH0790164A - Resin composition - Google Patents

Abstract

PURPOSE:To provide the title composition which can give a polybutylene naphthalenedicarboxylate(PBN) molding reduced in a coefficient of dynamic friction. CONSTITUTION:100 pts.wt. PBN is mixed with 2-30 pts.wt. spherical silicone solid of a mean particle diameter of 0.1-30mum to obtain the title composition which can give a molding having a low coefficient of dynamic friction and being useful as a sliding member.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition, more specifically, polytetramethylene-2,6-naphthalenedicarboxylate (hereinafter abbreviated as PBN) which exhibits excellent heat resistance, mechanical properties and sliding properties. Regarding resin.

[0002]

2. Description of the Related Art Plastic materials generally have excellent self-lubricating properties, are lightweight, and produce little noise during sliding, so they are used as alternative materials for metals in sliding parts such as bearings, gears, cams and rollers. I am doing it. However, plastic materials have the disadvantages of lower heat resistance and inferior mechanical properties such as rigidity compared to metal materials, so their applications are limited to parts with relatively low load, and heat resistance and mechanical properties are limited. There is a strong demand for a plastic material which has excellent dynamic characteristics and has a low coefficient of friction and which can be used as a sliding component under high load.

Polytetramethylene-2,6-naphthalenedicarboxylate (PBN) resin is a material which can meet these requirements. PBN resin is a polyester resin that has better heat resistance than polytetramethylene terephthalate (PBT) resin, and has excellent mechanical properties, water resistance, oxidation resistance, and chemical resistance. The value of the letter of use is considered to be great.

However, although PBN resin has high heat resistance, water resistance, wear resistance and the like as compared with PBT resin, the friction characteristic, that is, the dynamic friction coefficient is PB.
It is comparable to T resin and cannot be said to be sufficient.

[0005]

OBJECTS OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to obtain a PBN resin composition having excellent friction characteristics.

[0006]

The present inventors have conducted extensive studies to improve the frictional properties of PBN resins, and as a result, found that a composition obtained by incorporating a specific amount of a specific silicone-based spherical solid into a PBN resin meets the above-mentioned object. The present invention has been found.

That is, the resin composition of the present invention comprises (A)
(B) Silicone spherical solids 2 to 30 having an average particle diameter of 0.1 to 30 μm per 100 parts by weight of polytetramethylene-2,6-naphthalene dicarboxylate (PBN) resin
It is a resin composition prepared by blending parts by weight.

The present invention will be described. In the polytetramethylene-2,6-naphthalene dicarboxylate (PBN) resin as the component (A) used in the present invention, the main acid component is 2,6-naphthalene dicarboxylic acid, and the seed diol component is tetramethylene. A polyester resin composed of glycol, that is, a polyester resin in which all or most of the repeating units (usually 90 mol% or more, preferably 95 mol% or more) are polytetramethylene-2,6-naphthalenedicarboxylate.

The PBN resin may be partially substituted with a copolymerization component, and examples of such a copolymerization component include phthalic acid such as terephthalic acid, isophthalic acid, phthalic acid, methylterephthalic acid and methylisophthalic acid. Derivative;
Naphthalenedicarboxylic acids such as 2,7-naphthalenedicarboxylic acid and 1,5-naphthalenedicarboxylic acid and their derivatives; 4,4'-diphenyldicarboxylic acid, 3,4'-
Diphenylcarboxylic acids such as diphenyldicarboxylic acid and derivatives thereof; Aromatic dicarboxylic acids such as 4,4'-diphenoxymethanedicarboxylic acid and 4,4'-diphenoxyethanedicarboxylic acid; succinic acid, adipic acid, sebacic acid, azelaine An aliphatic or alicyclic dicarboxylic acid such as an acid, decanedicarboxylic acid or cyclohexanedicarboxylic acid;
Aliphatic diols such as ethylene glycol, propylene glycol, hexamethylene glycol and neopentyl glycol; alicyclic diols such as 1,4-cyclohexanedimethanol; dihydroxybenzenes such as hydroquinone and resorcin and its derivatives; 2,2-bis ( 4-
Bisphenol compounds such as hydroxyphenyl) propane and 2,2-bis (4-hydroxyphenyl) sulfone; aromatic diols such as ether diols obtained from bisphenol compounds and glycols such as ethylene glycol; ε-oxycaproic acid, hydroxybenzoic acid acid,
Examples thereof include oxydicarboxylic acids such as hydroxyethoxybenzoic acid.

Further, trifunctional or higher functional compounds such as glycerin, trimethylpropane, pentaerythritol, trimellitic acid, and pyromellitic acid may be copolymerized within a range in which the PBN resin does not substantially lose the molding performance.

The PBN resin used in the present invention has an intrinsic viscosity of 0.5 or more when measured at 35 ° C. with o-chlorophenol, but 0.6 or less.
Those having the above intrinsic viscosity are preferable.

The PBN resin used in the present invention can be produced by a usual polyester production method, for example, a melt polycondensation reaction or a method in which this is combined with a solid phase polycondensation reaction. For example, 2,6-naphthalenedicarboxylic acid or an ester-forming derivative thereof (eg, lower alkyl ester such as dimethyl ester, monomethyl ester) and tetramethylene glycol or an ester-forming derivative thereof may be reacted by heating in the presence of a catalyst to obtain 2,6
-Polytetramethylene-2,6-naphthalenedicarboxylate can be produced by a method of polymerizing a glycol ester of naphthalenedicarboxylic acid to a predetermined degree of polymerization in the presence of a catalyst.

Component (B), a silicone-based spherical solid used in the present invention, is a spherical solid of a silicone compound having a siloxane bond as a basic structure, and silica, silicone rubber and silicone resin are preferred as the silicone compound.

Silica, that is, silicon dioxide, has a three-dimensional infinite regular tetrahedral structure of SiO ₄ obtained by a method of oxidizing silicon or a hydride of silicon with an oxide such as oxygen or water. It is a compound.

Silicone rubber and silicone resin are polymer compounds having an organosiloxane bond as a basic structure, and dichlorodialkylsilane gives silicone rubber and trichloroalkylsilane gives silicone resin. A methyl group is most preferable as the alkyl group, but a vinyl group, a phenyl group and the like can be used alone or in combination.

These silicone-based spherical solids having an average particle diameter of 0.1 to 30 μm are used. If the average particle size is smaller than 0.1 μm, the compound becomes bulky and difficult to handle, and problems such as poor dispersion occur during compounding with the PBN resin, which is not preferable. 30 μm
When it is larger, the mechanical properties of the PBN resin are deteriorated, which is not preferable.

The PBN resin has heat resistance, water resistance, oxidation resistance and chemical resistance superior to those of the PBT resin, but its friction characteristics show only the same level of dynamic friction coefficient as PBT. However, when the above-mentioned silicone-based spherical solid is blended with this PBN resin, the dynamic friction coefficient is greatly reduced, and a composition useful as a sliding member is obtained.

The amount of the silicone type spherical solid of the component (B) is 2 to 30 parts by weight per 100 parts by weight of the PBN resin. If the amount is less than 2 parts by weight, the effect of improving the frictional properties of the PBN resin is small, and if it is more than 30 parts by weight, the mechanical properties of the PBN are deteriorated, which is not preferable.

A pigment or other compounding agent may be added to the resin composition of the present invention in an expression amount, if necessary. Such compounding agents include fillers such as glass fiber, aramid fiber, carbon fiber, steel fiber, ceramic fiber, potassium titanate whiskers, fibrous substances such as boron whiskers, kaolin, clay, wollastonite, talc,
Examples thereof include powdery, granular or plate-like inorganic fillers such as mica, calcium carbonate, barium sulfate, glass beads and glass flakes.

These fillers are usually blended as a reinforcing material, a surface modifying material, or for the purpose of modifying electrical and thermal properties, etc. It should be blended within a range that does not lose the excellent properties inherent to the product and the advantages in molding.

Also flame retardants such as brominated polystyrene,
Brominated polyphenylene ether, brominated epoxy, brominated bisphenol-A-diglycidyl ether and its oligomers, polycarbonate oligomer produced from brominated bisphenol-A as a raw material, brominated biphenyl ether, brominated diphthalimide compound, chlorinated hexa Halogen-containing compounds such as dimers of pentadiene; phosphorus compounds such as red phosphorus and triphenyl phosphate; phosphorus-nitrogen compounds such as phosphonamide; triazine compounds such as melamine, melam, melem, melon, cyanuric acid and melamine cyanurate. Flame retardant aids used in combination with or alone in combination with metal hydroxides such as aluminum hydroxide, magnesium hydroxide, dawsonite, gypsum dihydrate and the above halogen-containing compounds, eg antimony compounds such as antimony trioxide, acids Boron, it is possible to blend the metal oxides such as iron oxide.

Further, for the purpose of improving heat resistance, an antioxidant or a heat stabilizer such as a hindered phenol compound, an aromatic amine compound, an inducing phosphorus compound and a sulfur compound may be added. Various epoxy compounds, oxazoline compounds and the like may be added for the purpose of improving melt viscosity stability and hydrolysis resistance. Examples of the epoxy compound include bisphenol-A type epoxy compounds obtained by reacting bisphenol-A with epichlorohydrin, aliphatic glycidyl ethers obtained from reaction of various glycols or glycerol with epichlorohydrin, novolac type epoxy compounds, aromatic or fatty compounds. Group carboxylic acid type epoxy compounds, alicyclic compound type epoxy compounds and the like are preferable, and as the oxazoline compound, aromatic or aliphatic bisoxazoline, particularly 2,2′-bis (2-
Oxazoline), 2,2'-m-phenylene bis (2-
Oxazoline) is preferred.

Other stabilizers, colorants, lubricants, UV absorbers and antistatic agents can also be added.

Furthermore, a small amount of other thermoplastic resin such as other polyester resin, polyamide resin, polyphenylene sulfide resin, polyphenylene ether resin, polycarbonate resin, phenoxy resin, polyethylene and its copolymer, polypropylene and its copolymer. Polymers, polystyrene and copolymers thereof, acrylic resins and acrylic copolymers, polyamide elastomers, polyester elastomers and the like; thermosetting resins such as phenol resins, melamine resins and unsaturated polyester resins may be blended.

Any compounding method can be used to obtain the resin composition of the present invention.

Usually, it is preferable to disperse these compounding components more uniformly, and a method of mixing all or part of them simultaneously or separately with a mixer such as a blender, a kneader, a roll or an extruder for homogenization, It is possible to use a method in which a part of the mixing portion is mixed simultaneously or separately with, for example, a blender, a kneader, a roll, an extruder, etc., and the remaining components are mixed with these mixers or an extruder to homogenize. Further, there is a method in which the composition dry-blended in advance is melt-kneaded by a heated extruder to homogenize it, then extruded into a wire shape, and then cut into a desired length and granulated.

The molding composition produced in this way is
Usually, it is kept in a sufficiently dried state and put into a hopper of a molding machine and used for molding such as injection molding. Further, it is also possible to dry-blend the constituent raw materials of the molded product and directly put into the hopper of the molding machine and melt-knead in the molding machine.

[0028]

EXAMPLES The present invention will be described in detail below with reference to examples. In addition,
Various properties in the examples were measured by the following methods. (1) Mechanical properties: Tensile test conforms to ASTM D638. (2) Deflection temperature under load: According to ASTM D648. Load 1.81 MPa. (3) Intrinsic viscosity: measured at 35 ° C. with an Ostwald viscous tube using o-chlorophenol as a solvent. (4) Sliding and ward administration: In accordance with JIS K7218 A method.
Using a hollow cylindrical test piece, steel mating material, load 40k
The friction coefficient was measured at g and a speed of 20 cm / sec.

[0029]

Examples 1 to 6 and Comparative Example 1 PBN resin (Teijin Co., Ltd.) with an intrinsic viscosity of 0.77, which was dried with hot air at 130 ° C. for 8 hours.
Made of silica), and an average particle size of 1 μm silica (CRS, Tatsumori Co., Ltd.)
Manufactured), powdered silicone rubber with an average particle size of 5 μm (KMP
594, manufactured by Shin-Etsu Chemical Co., Ltd. and powdered silicone resin having an average particle size of 2 μm (KMP590, Shin-Etsu Chemical Co., Ltd.)
(Manufactured) at a ratio shown in Table 1 and then uniformly mixed with a tumbler in advance, and then a twin screw extruder with a vent having a screw diameter of each 44 mm is used to evacuate the cylinder temperature 285 ° C.,
Screw rotation speed 180 rpm, discharge rate 50 kg / hr
Was melt-kneaded, and the thread discharged from the die was cooled and cut to obtain pellets for molding.

Then, using the pellets, an injection molding machine having an injection capacity of 5 ounces, a cylinder temperature of 280 ° C., a mold temperature of 120 ° C., an injection pressure of 80 MPa, a cooling time of 15 seconds,
And a molded product for each characteristic measurement was molded under the condition that the entire molding cycle was 40 seconds.

[0031]

[Table 1]

Each characteristic was measured using these molded products. The results are shown in Table 1.

The PBN resin is a resin having excellent heat resistance and mechanical properties, but its dynamic friction coefficient shows a relatively high value (Comparative Example 1). However, when silica, a powdery silicone rubber, or a powdery silicone resin is blended with the PBN resin as a silicone-based spherical solid, the dynamic friction coefficient is remarkably reduced (Examples 1 to 6). At that time, the mechanical properties are represented by HDT, and the heat resistance maintains the properties of PBN (Examples 1 to 6). Compositions having improved sliding properties while retaining the features of PBN resin Will be obtained.

Claims (4)

[Claims] 1. (A) per 100 parts by weight of polytetramethylene-2,6-naphthalene dicarboxylate resin,
(B) A resin composition containing 2 to 30 parts by weight of a silicone-based spherical solid having an average particle size of 0.1 to 30 μm. 2. The resin composition according to claim 1, wherein the silicone spherical solid of the component (B) comprises silica. 3. The resin composition according to claim 1, wherein the silicone-based spherical solid of the component (B) comprises silicone rubber. 4. The resin composition according to claim 1, wherein the silicone spherical solid of the component (B) comprises a silicone resin.